This proposal is for support of personnel and facilities for the collection and extraction of erythropoietin from urine of patients with severe anemia in order to study methods that may lead to improve yields of material concentrate with high crude specific activity, standardization and ultimate distribution by the N.H.I. for use in fundamental research on Erythropoiesis by qualified investigators. Asuncion city, the capital of Paraguay, has one of the world's highest rates of hookworm infection and among the patients, severe iron deficiency anemia is common. The Clinic Hospital of the University of Asuncion with an 800 beds' capacity receives in its children department (90 beds), an average of 30 percent patients, with ages ranging from 2 to 14 years, that suffer from anemia under 5 gr percent hemoglobin. An Urine Collection Program can be started in the Hospital of Asuncion, as it has such a large number of anemic patients. Crude material may be obtained in this hospital and assaying, checking and final delivery to N.H.I. would be done in the Neurobiology Institute of Buenos Aires, Argentina. Our experience in erythropoietin research goes back to 1960 and we are the only ones to combine a staff of investigative personnel experienced in applicable laboratory techniques. Large amounts of available raw material led to the establishment of this program in September 1966. Since then, this program has provided a reliable source of human erythropoietin to support basic and applied research by investigators throughout the world. It is believed that this program provides the least costly, most reliable and most abundant source of erythropoietin and that it is as well the only program in work for the collection of human erythropoietin.